Electrical connecter



July 31, 1928.

1679067 A. B. WISEMAN ELECTRICAL CONNECTER 2 sheets-sheet 2 Filed Sept.12, 1925 II h v Imw m Patented Jul 31, i928.

ALBENUS'B. wrsnman, or GRAND RAPIDS, ufcnxean.

ELECTRICAL connncrna.

Application filed September 12, 1925. Serial No. 56,011.

This invention relates to improvements in electrical connecters andwhile designed primarily for use in connection with portable electricmotors, may be employed in making electrical connections between asource of current supply and various other electrical machines orapparatuses.

One of the objects of the present invention is to provide a connecterembodying a socket and a plug insertable therein and in which the socketwill be so constructed that allcontacts therein will be completelycovered when the plugis not in place,so that a workman will not beliable to be injured by v coming in contact with any live wiresor'contacts when inserting or removlng the plug or even if, throughignorance, he should insert J his fingers into the socket. Likewise, theinvention contemplates aconnefcter embodying a socket so constructedthat the insertion of a-tool or any other metallic object into the plugwill not cause disasterous results. 7

Another object of the invention is to so construct the, connecter thatwhen the plug is properly inserted it can not'be directly pulled out ofthe socket or otherwise. displaced to cause short circuiting orimperfect contact of the coacting conductor terminals of the plug andsocket.

Another object of-the invention is to provide a connecter .soconstructedthat, when the plu the con uctor contacts within the plug'will beprotected-by an insulating medium in such a manner as to prevent injurythereto or water coming in contact therewith Another object of theinvention 1s to so construct the connecter that the ccnductor terminalsof he plug and socket 'wlll be securely held in mutual engagement whenthe plug is properly inserted into the socket,'so that there can be noimperfect contacts between the parts which might result in'dam--agingthevmotor or other machine or apparatus to beisupplied withcurrent. I

In the accompanying drawings:

Figure 1 is a vertical sectional view through an electrical connecterembodying the invention.

Figure 2 is a vertical front to reat sectional view through the socketof the connecter, the plug being removed. v

Figure 3 is 'a horizontal sectional view taken substantiallyon the line3-3 of Figure 2, looking in the direction indicated by the arrows.- j

is either inserted or not inserted.

Figure 4 is a perspective view illustrating a set of the plug andsocketconductor terminals in position about to be engaged.

Figurej is a top plan view of the plug, one of the conductor terminalsofthe plug beln shown in section.

Figure 6- is a diametric sectional View takensubstantially on the line6-6 of Fig ure 5, looking in the direction indicated by the arrows.

Figure 7 is a perspective viewof the insulating member'of the socket.

Figure 8 is a sectional view. illustrating a modification in theconstructionof the conductor terminals of the socket In the illustratedembodiment of. the invention, the connecter is designed for use inconnection with motors of the three-phase type with ground connection,two-phase type without ground connection, or single-phase type withground connection. and the socket of the connecter is designed forattachment to any suitable fixed support such as a" wall.

The said socketcomprises a cylindrical metallic body shell indicated bythe numeral 1. and provided ,intei'iorly at its open lower end with anannular flange 2 and, exteri rly,

at its )open upper end with an outstaning annular flange 3. A capsection 4 is provided to close the upper endof. the body shell 1 and isof dome-like form, the cap section being provided interiorly at its openbottom with an inwardly projecting annular flange 5 into which arethreaded bolts 6 which are engaged through openings in the' flange 3 ofthe body shell 1, to secure the parts together, a packing gasket 7 beingin-- terposed between the flanges 3 and 5 so as.

to insure against the entrance of moisture between the flanges. The capsection 4 is provided at its rear side with an attaching portion Shavingopenings 3 through which any suitable securing elements such'as sorews.

or bolts may be engaged for the purpose .of securing the tap section toa fixed support, and thereby support the socket as a whole, and inadvance of the said attaching portion and in its upper side, the capsection 4 is formed with a threaded opening 10 into which may befitted'a conduit. (notshown) for the conductor wires which lead into thesocket and are indicated by the numeral 11.

Arranged within the body shell 1* of the plug is a body 12 of insulatingmaterial;

, preferably porcelain, and :inorder to accommodate the plug which willpresently be 3 a conductor terminal or contact indicated contactcomprises a'base portion 22 which is inasmuch as-the .contacts 21 are ofa width described, the said body is formed axially lation. Screws 32 arethreaded through the with a cylindrical bore indicated by the body 12 ofthe socket and are threaded 1nt0 numeral 13, the bore opening throughtheopenings 33 formed im the bases 22 of the upper and lower ends of thesaid body 12 several cofitacts, and it'willbe observed that and the saidbody being supported at its botin this manner the contacts are securedin tom upon the flan ge 2, as best shown in Figplace with their bases 22resting upon the ures 1 and 2 of the drawings. An annular bot-tom walls19 of xthe respective recesses. flat gasket 14 of insulating material isdis- The screws 32 passalso through conductor posed upon the upper endofthe body 12, strips 34' which are disposed against the 1nand an annularmetal plate 15 is disposed ner walls of the respective recesses 18 andupon the upper side of the gasket .14, bolts preferably seated flush insald walls as shown 16 being fitted through the flange 2, the body inFigure 3 of the drawings; The screws 12, gasket 14, and plate /15, andnuts 17 be- 32 pass through the lower ends of the strips ing threadedupon the upper ends of the 34' and the upperends of the strips aresebolts 'to bear against the upper side of the cured by screws 35 fittedthrough the outer said plate 15 and thus secure the parts in side of thebody 12 and threaded intoopentheir assembled" re ation. lugs 36 formedin the upper end portions of A series of recesses 18 is formed in thethe respective strips 34. Each strip 34 at wall of the bore 13 of thebody 12 and open lts upper end is formed with incisions and at theirupper ends throu h the upper'end bent to provide wire gripping lugs 37and:

of the body and at their l owerends termithe conductor wires 11 are ledthrough insunate approximately midway between the uplating bushings 38in the'plate15, and are .per and lower ends'of the body, the bottom,anchored by the lugs 37. to the respective wallspf the said recessesbeing indicated by conductor strips 34. Where'- three leads or thenumeral 19. Grooves 20 are likewise conductors are present in thecircuit, they formed-in the wall of the .bore 13 and extend areconnected to three of the conductorstrips vertically and open at theirlower ends 34' and where a ground is employed the con through the'bdttom of the body 12 and at' ductor wire wh ch is indicated by thenumeral their u per ends through the tsp of the said 39, is connected tothe fourth one of the conbody, t e groovesbeing loca at one side ductorstrips 34, at one end and at its other of a respectiveone of therecesses 18,so that end by a blnding screw 40, to ,a boss 41 therecesses have open sides presented to formed upon the inner side. of thecap sec their respective grooves. tion 4 at the front thereof, as bestshown in Arranged within each of the recesses '18 is Figure 2 of thedrawings, so that this particular contact is grounded by way of theeasof the socket. 7

general by the numeral ,21 and most'clearly in'g[t will be evident fromth f th fi e oregoing k a shownin Figure 4 of the drawings. -This ofmetal and which has an integral u standsubstantially equal tm the widthoffthe re ing contact finger 23 the upper'end 0 which cesses in whichthey are housed, the edges is rounded as at 24, for a purpose which willof thecofitact fingers 23' and'25 will be prepresently be made apparent.The contact sented inwardly at the surface of the wall loo nger 23 beingintegral with the base 22, is, of .the bo r e 13 in the body 12, and inorder J of course, fixed, and the contact as a whole to preclude ahypossibility of a workman comprises a second contact finger which/isshort circuiting any of the contacts by careindicated bythe .numeral 25and of substan-J lessly-inserting' tools or other metallic obtially thesame contour as thefinger 23, bejects into the socket, and likewise "inorder ing provided with a rounded end 26, This to provide against injries which would contact finger 25 'is yieldably supported in result ifhe inserted h's fingers mto the a manner which will now be explained. Asocket a d the contacts were exposed, means thin copper leaf 27 and asteel spring leaf is provided for shielding the contacts when 28 aredisposed in overlappiiig relation and the plug is not inserted in thesocket, this are secured at their lower ends, by screws 29, featureconstituting also, as willbe presently to that end of the base 22opposite the end explained, a medium whereby the plug will whichsupports the finger 23. Screws 30 are be securely held in place whenproperly secured through the leaves 27 and 28 and fitted into thesocket. The means referred threaded into the outer side of the finger toabove comprises a metallic shell 42-which 25, and the leaves are formedwith a slight is preferably of rectangular formfand open bend, asindicated at 31, near their lowerat its bottonf where it is providedwith a ends and immediately above the upper surflange 43 through whichsecuring elements face of the base 22, so that the finger 25 is 44 areengaged to secure the shell to the yieldably supported in apositioninclining upperside of the plate 15 and insulating toward the finger 23,the rounded upper ends gasket.14.- -The; openings in the said gasket ofthe fixed'and yieldable fingers] being loor disc 14 and the plate15 areindicated cated opposite each other and in spaced re.- respectively bythe numerals 45 and 46, and

V Y A J. i

the numeral 47 indicates a cylindrical body of fiber or other suitableinsulating mate-v rial which is slidably fitted through the saidopenings 45 and 46. The body 47 is provided at its upper end with asubstantially rectangular head 48 which more or less snugly fits withinthe shell 42, so that rotation of the body 47 is preventediand yet thebody may have free up anddown movement through the openings45 and 46.

' The openings 45 and 46 are of the same.

diameter as "the bore 13 of the body 12 and it will be observed byreferenceto Figure 2 of the drawings, that nornially the body occupies aposition filling the upper end of the bore and completely covering the'one end fits over a. boss 53 at the upper end of the guide and at itslower end fits overa similar boss 54 secured'in place by a pin 55 whichextends through the lower end oi'the body 47 of the insulating shieldand which pin is provided with a head 56 constituting an abutment andwear element. 'Ey reference to Figure 2, it will be observed that thespring normally holds the member 47 in the lowered position in which itfills the upper end of thebore 13 and covers and protectsthe contacts21, and it will further be observed by reference to'this figurethat inthis position of the member, the head 48 restsrat its under side upmnthe upper side of the plate 15 adjacent the ope ning 46 therein, so thatby reason of this mutual engagement .of-the parts, the downward movementof the member "47 is limited.

.The plug of the connecter is indicated in general by the numeral 57 andthe same comprises a one piece body portion 58 and handle 61 cylindricalin form'and of some suitable insulating material such for example ashard maple wood. The body is formed with an axial bore 59 which at oneend communicates with a bore 60 formed in the handle 61. A circularguard 62 is provided at the juncture of the body 58 and the handle 61arid may be of rubber or other insulating material so as. to protect thehand of the user when inserting the plug into the socket. The bore'59-,0f the plug body 58 terminates short of the opposite end of thebody or, in other words, the end,

which is to be introduced into the bore 13 of the socket, and a seriesof slots 63 etc formed in the said body 58 near its said end andcommunicate with the bore 59, the

slots corresponding, of course, in number to the number of contactswhich are to be carried by the plug body. These contacts are indicatedin general by (the numeral 64 and each comprises a metal body having ahead portion 65 provided with a depending nose 66, the lower side, ofwhich is transversely rounded as at 67, so as to adapt the same toreadily enter between the rounded upper ends 24 and 26 of the contactfingers 23 and 25 of the respective contacts 21 when the plug is fittedintothe socket. The head 65 of each of the contacts ,64 is formed withan opening 68, and a screw 69 is fitted through the opening and threadedinto a bushing 70 embedded in the plug body 58. Conductor strips 71 aredisposed flush in the surface 'ofthe body 58 above the upper ends of theslots 63 and between the body and the inner "sides of the respectivecontacts 64, the. roundedlower side 67 of each contact being locatedimmediately at the upper end of a respective one of the said slots. Each*conductorstrip 71 is turned inwardly at rightangles'as at 72, againstthe top wall of the respective slot 63, and thence downr wardly at rightangles, as' at 7 3, against the upper-portion of the inner wall of therespective slot, and securing screws 74 are fitted through these latterportions of the conductor strips and are threaded into bushing 7 5embedded in the insulatorplug body 58. \A cable 76 is led firom themotor or other electrical apparatus or machine to-be supplied withcurrent, through the bore 60 of the handle 1, which handle is preferablytreated with a suitable water-proofing com position, and the wiresconstituting a part of this cable and indicated by the numeral 77, areled through respective ones of the conductor strips 71 and connected bybinding screws 78 to the projecting lower end portions 73 of saidstrips. An abutment and wear element 79 is preferably secured to the endof the plug body 58 to contact the corresponding element 56 of thesocket.

By comparison of Figures 3 and 5 of the drawings, it will be observedthat the grooves 20 and the contacts 64 are of such dimensions that thecontacts may enter the lower ends of the grooves, at the time .theplug-is inserted into the Socket, and

pass upwardly through the grooves to.

coact with the respective contacts 21 when the plug has been rotated tothe right a short distance; approximatgly one-eighth of a revolution,and the' spring 52 has expanded to forcethe plug 'in an outwarddirection, or the handle 61 is manually pulled outwardly, it beingunderstood that at the time of insertion of the luginto the socket, theinsulating shield 4 will be forced inwardly against the tensioneof thespring 52. It will nowbe evident, by reference to Figure 2 of thedrawings, that when the plug isnot inserted in the socket, the

;circuiting can occur if a careless workman should inserta tool or othermetallic ob ect into the socket. Likewise, as the plug is fitted intothe socket, the plug body will occupy the space formerly occupied by thelower portion of the insulating body 47, so that the vcontacts of boththe socket and plug are protected as in theformer instance. It will alsobe evident from the foregoing that the pressure exerted by theinsulating body 47 through the medium of the spring 52, against the plugbody 58, when the coiltacts of the plug are in engagement with thecontacts of the socket, insures against any accidental disarrangement ofthe arts and likewise insures against the plug bcing accidentally pulledout of the socket it any strain is imposed upon'the cable;76, inasmuchas to disengage the plug front the socket it is necessary to shove theplug igwardly and then rotate theSame to bring t e plug contacts intoalinement with the respectiveslots 13, referencdto'Figures 3 and 5 ofthe drawings, it will also be observed that one of the grooves shown inFigure 3 is of less width than the other grooves, and likewise one ofthe contacts shown in Figure'5, is of less thickness than v the othercontacts, and thereforegit is impossible for the plug to be insertedinto i the socket except in ,the proper and intended manner. It will,furthermore, be evident that inasmuch as the contacts of the plug areheld firmly in engagement with the contacts within the socket,throughthe pressure exerted by the spring 52agairist the insulating body147, and likewise due to the frici tional engagement of the noses 66 ofthe q contacts 64 between the fixed and yieldabl'y supported fingers ofthe contacts 21, there can be no play between the contacting parts suchas would be liable to cause arcing or .Figure 8 of the drawingsillustrates a modified form-ofsopket contact and in this figure, thenumeral-SOindicates in general the contact which is mounted in thelsamemanner as the contact shown in-Fi'gur 4 of ;the drawings and includes abase port on 81 correspondingto the base portion 22 of the (previouslydescribed contact, and a fixedv from. In this embodiment, the yieldablecontact finger is indicated bythe numeral 83 and the same is supportedby spring leaves 84: corresponding to the leaves 27 and 28, at that endof the base portion 8L opposite the end from, which the contact \82extends. In this embodiment, however, a screw 85 is threaded at one endinto the yieldable finger i, 83 and extends loosely through a slot 86formed in the fixed contact finger 82, a spring 87 being arranged upon,the said screw-to bear between the head 88 thereof and the outer sideof/ the finger 82, so as to yieldably draw the finger 83 toward thefinger 82. f

Having thus described the invention,what I claim is: V

1. An electrical connecter; comprising a socket, and a plug, the socketincluding a body of insulating material having a bore to receive theplug, said bore having open sided vrecesses in its wall, a pluralitypfcontacts supported by the body and arranged within the" recesses, aplurality of contacts upon the plug for engagement with thefirst'mentioned contacts when 'the plug is inserted into the bore, andan insulator movable within the boreand'nor'mally occupying a POSltiODfor closing the open sides of the recesses for shielding the firstmentioned oa" contacts and displaceable' by the plug upon itsinsertioninto the bore, said plug and insulator having intimate sliding with thewall of thebore. v

2. An electric connecter comprising a socket, and a plug, the socketincluding a body of insulating material having a bore to receive theplug, said'bore having open' sided recesses in its wall, contactssupported by the body and arranged intherecesses, a plurality ofcontacts upon the plug for engagement with the first mentionedcontactswhen the plugis inserted into the bore, an insulator movablewithin the bore and normally occupying a position for closing the opensides of the recesses for shielding the first mentioned contacts anddisplaceable by the engagement,

\ the lbs plug upon its'insertio'n into the bore, said I I plug andinsulator having I intimate sliding means yieldably holding theinsulator said normal position,

3. An velectrical connecter comprising "a socket, and a lug, thesocketincluding a body gfinsulatlng material having a bore to receive theplug, the said bore Being cylindrical and having grooves and recessesformed in its walls, a'plurality'of contacts supported by the body andarranged about Q. i

v the wall of the bore in said recesses and rel-' atively displaced withrelation to the upper end of a respective one of 'the grooves, a

plurality of contacts upon the plug engage- ,seftion of the plug intothe boge and enable through the grooves at the time of in,-

"on engaging the first mentioned contacts,

said insulator also serving to shield the first mentioned contacts whenthe plug is withdrawn from the bore of the body.

4. An electrical connecter comprising a socket, and a plug, the socketincluding a body of insulating material having a bore to receive theplug, the said bore being cylindrical and having grooves and recessesformed in its Walls, contacts mounted in-the recesses and relativelydisplayed with relaa plurality of contacts upon the plug en-' gageablethrough the grooves at the time of insertion of the plug into the boreand engageable with respective ones of the first mentioned contacts,when the plug is rotated after insertion, a cylindrical body ofinsulating material movable longitudinall within the bore and havingintimate'sli ing engagement with the wall of the bore, and a springcoacting with' the said body and yieldably normally holding the same inposition to close the recesses shielding the first mentioned contacts.

In testimony. whereof I aflix my signature.

.. l AliBENUS B. WISEMAN. a s.]

